Arrangement in separators for prevention of foam creation



Jan. 9, 1940. J. G. DEGERTH I 2,186,822

ARRANGEMENT IN SEPARATORS FOR PREVENTION OF FOAM CREATION Filed Dec. 6, 1935 INVEINTOR ATTORNE s I Patented Jan. 9, 1940 v UNITED sTATEs ARRANGEMENT IN SEPARATORS FOR PRE- VENTION OF FOAM CREATION John Gustaf Degerth, Helsingfors, Finland, assignor, by mesne assignments, to Wartsila- Yhtyma /Y.-Wartsila-Koncernen A/B, Vartsila, Finland, a corporation of Finland Application December 6, 1935, Serial No. 53,247

In Finland December 29, 1934 1 Claim.

This invention relates to improvements in separators, and has particular relation to centrifugal fluid separators.

When separating certain fluids such as milk by centrifugal force, there is a tendency to create foam and various arrangements have been suggested to prevent this. Frequently so-called Skimmers have been used for this purpose, in

. which the speed with which the fluid rotates with the bowl is converted into pressure. This pres-- sure is then employed so that the fluid will leave the separator at the desired outlet speed and at the desired pressure. In stationary separators these arrangements are preferably placed at the ment of the skimmer in the upper part of the bowl has, however, caused certain difficulties regarding the construction and assembling, and

amongst other things it has been diflicult to lead the fluid to be separated past the skimmer disc into the inner outlet-chamber of the bowl.

It is an object of this invention to provide a suitable solution of this construction problem.

In carrying out my invention the fluid is led from channels formed inside the skimmer at first to a bigger space situated around the feed pipe and then further on by one or several channels to the outlet pipe placed within the feed pipe in the longitudinal direction of same. The channels are placed so that the fluid to be separated is not obstructed and further passes through the feed pipe to the inlet chamber of the bowl. The arrangement is suitably carried out so that the feed pipe is tightened together with the skimmer by one single nut, placed on the outlet pipe which is branched oii from the skimmer so that the parts can be taken apart after having removed the nut.

On the accompanying drawing is shown an example of one way in which the invention can be carried out.

Fig. l is a vertical section through the upper part of a separator equipped with the above mentioned arrangement for preventing the creation of foam;

Fig. 2 is a section in the direction of line cd in Fig. 1; and

Fig. 3 is a section in the direction of line 0-1) in Fig. 1.

In the upper part of the rotating bowl a space I is arranged in which the arrangement for preventing of foam is placed. This arrangement consists of a stationary annular part or skimmer 2 closed on all sides, theoutside cylindrical wall of which is reaching so far into the vertical surface of the fluid that the fluid entering into the skimmer does not come into contact with air and thus remains free from foam. Said cylindrical outside wall is furnished with a slit 3. This slit is best turned obliquely downwards, however the same can also be arranged vertically and pass downwards. In the annular space inside the skimmer insertions 4 are placed between which are the channels 5. The channels 5 extend on account of the shape of the insertions 4 at first in nearly a radial direction inwards and pass into a central annular space 511. It should be noticed that the insertions 6 do not extend up to the periphery, but leave the required space for the uninterruptedly-annular slit '3, which is intended to finally prevent casual air particles from following with the fluid up into the channels of the skimmer. Tests carried out show that owing to the fact'that the fluid in the slit 3 still can continue to rotate somewhat, prior to entering the channels 5, the creation of foam will be substantially reduced. From the outside towards the inside the channels 5 become larger and their greatest width nearly corresponds with the width of the annular space. The annular space 511 is confined inwards by the pipe 5?) which is used as feed-pipe for the fluid to be separated, and in this pipe a pipe t is inserted, which latter pipe has a relatively small cross-section-area. The pipe 6 connects the interior of the annular part 2 with the discharge pipe l4, extending in a vertical direction and intended for the separated fluid.

In the upper part of the separator bowl two sets of discharge channels are arranged, viz. vertical channels I through which the heavier component of the separated fluid, which component in the present example is subjectto foam creation, rises upwards. The fluid flows upwards along the top disc 8 of the separator. Further a space 9 is arranged in which the lighter component of the separated fluid enters through openings below the top disc 8 in the direction which is indicated by the arrows with three angles at the end. This space is closed towards its upper part by a partition wall 2! and is connected with a collecting vessel by channels H) which lead outwards between the channels 1 and cross same.

The fluid which is to be separated is carried through the angle-shaped pipe indicated by the numerals l2 and II. The pipe I l surrounds the discharging pipe l4 and a nut l3 placed on the latter pipe serves for keeping the parts 2, l I and I2 together. In the pipe H a number of openings l5 and I6 are arranged and the space within the pipe is divided in two parts by a flange Ma on the pipe M. The pipes Ii and M are placed within a float vessel I! put on the separator in which vessel a float 2c is placed. The latter is connected with a pipe 290, surrounding the pipe H. The pipe 20a is equipped with openings 22.

The arrangement described above works as follows: The fluid which is to be separated flows in through the way indicated by the arrows equipped with an angle, viz. through the pipes l2 and II and thereupon through the openings I5, 22 in the float vessel I? and from same through the openings I6, 23 and I8 into the separator bowl. In case too much fluid enters into the float vessel 11, the float rises together with the pipe 20a, so that the openings 22 and i5 cover each other less and less and finally not at all and in this way the further supply of fluid to the separator is throttled or shut off. The lighter non-foaming fluid rises in the space 9 and leaves through the channels The heavier foaming fluid travels through the channels I and the slit 3 into the skimmer 2. In the skimmer the flowing energy of the entering fluid is converted into pressure on account of the radial and diverging arrangements of the channels. The fluid rises then under pressure through the pipe 6 up in the pipe I l and leaves through this pipe which gradually grows larger at 19. The continual discharge takes place under pressure so that the fluid which is discharged can overcome the reaction which arises from resistance in the other machines in which the fluid is treated. In certain cases pressure is also necessary in order to transfer the fluid to a collecting vessel placed on a higher level.

On account of the opening 3 being made in the shape of a narrow slit which is best turned obliquely downwards, the access of air into the interior of the skimmer 2 is prevented. Consequently no Whirlpools, which could cause trouble, can arise. Instead of a single slit 3, of course, several slits can be arranged concentrically one above the other.

Owing to the fact that the discharge pipe l4 leads through the feed pipe I E for the fluid which is to be treated, it is possible to attain a simple. space-saving construction which may be considered as the principal advantage of the present arrangement as compared with previously known arrangements.

I claim:

A centrifugal separator comprising in combination a bowl rotatable on a vertical axis, a vertical feed pipe extending axially of the bowl from the upper part thereof for conducting to the bowl the fluids to be separated, a stationary annular shaped skimmer disposed around the feed pipe adjacent the upper portion of the bowl, said bowl at its upper end being provided with a structure forming a chamber and enclosing the skimmer and adapted to retain a Wall of the separated heavy fluid therein and being provided with a passageway for conducting the heavier separated fluids from the separating zone of the bowl to the chamber. said skimmer being or" a diameter great enough to penetrate the wall of heavy fluid in said chamber and comprising an annular casing provided with a peripheral obliquely downward extending slit and having means inside the casing forming an annular space surrounding the said pipe, and generally radial channels extending from the slit in the casing to the space and expanding in size from the slit to the space, the space being of relatively larger size than the channels, and an outlet pipe for the heavier separated fluids disposed in the said pipe longitudinally thereof and having communication with the space so as not to obstruct entry into the bowl through the feed pipe of the fluid to be separated.

JOHN GUSTAF DEGERTH. 

